Lamp changer



May 9, 1939 F. c VPETHlcK v 2,157,563

LAMP CHANGER y Filed Jan. 2, 1937 NvENTuR MC1 Patented May 9, 1939 UNITED STATES PATENT orrics rmi c. Pethick, Scranton, Pa..

Application `anuar'y 2, 1937, Serial No. 118,792

6 Claims.

My invention relates to lamp changers, more particularly to lamp changers of the vacuum cup type, and the invention has for its' object the provision of an improved and smpliiied device of this character.

Lampchangers generally comprise a pole, at the upper end of which is a device for gripping or otherwise taking hold of the lamp bulb which is to be removed or replaced. By using a lamp changer it is possible toremove or replace lamp bulbs located in elevated sockets without the'use of a ladder or the like.

It is desirable in this type of apparatus that the device which grips or takes hold of the lamp be such that there will be no danger of breaking the glass globe of the lamp, but .on the other hand it is also desirable that the gripping device provide sufficient holding power so that by using the lamp changer a burned-'out lamp can be manipulated out of an elevated socket and a new lamp manipulated into the socket without any danger of the lamps being dropped. It is also generally desirable to have some means of releasing the hold which the lamp changer has on the lamp after it has been manipulated into the socket. A. further very desirable feature is to have the gripping device so arranged that it will perform the above functions equally well on all the common sized lamp bulbs. This has been practically impossible with lamp changers of the vacuum cup type heretofore generally used because lamp changers oi this type have been arranged to grip only one size of lamp bulb. This has necessitated having a different size lamp changer or at least a different sized vacuum cup for each diierent size lamp bulb to be handled. Also lamp changers of the vacuum cup type, if

. they have provided sucient holding power so that by their use the lamp could successfully be manipulated into and out of the' socket, also have held the lamp, with such a strong grip that without means for releasing this grip it has been dicult to separate the lamp changer from the lamp after the lamp has been manipulated into the socket. In fact if no releasing device is provided, it is possible to break the lamp bulb or the fixture by the pull exerted on the lamp changer to separate it from the lamp.

My invention contemplates the provision of an improved la'mp changer with a single vacuum cup which will grip any of the various sized spherical lamp bulbs or lamp bulbs having a convex lower end on the bulb with sufficient holding power so that they can be manipulated into or out of an elevated socket without any danger of the lamps 'manipulated into the socket.

It is a still further object of this invention to provide an improved vacuum cup gripping device for lamp changers.

In accordance with this invention in one form thereof a suitable vacuum cup is arranged at the upper end of a pole, and a cord or wire is arranged to extend from the vacuum cup to a point at or near the lower end of the pole.

By the use of my invention any of the common sized spherical lamps or lamps having a convex end on the bulb can beremoved from or placed into elevated sockets without any danger of breaking or dropping the lamp or without any undueY strain being placed on either the bulb or fthe socket.

For a more complete understanding of this invention, reference should be had to the accompanying drawing in which:

Fig. l is an elevation of a lamp changer embodying this invention;

Fig. 2 is a duplicate of Fig. l except that it showsthe lamp changer embodying this invention about to grip a larger sized lamp than is shown in Fig. 1;

Fig. 3 is a horizontal section view taken through the line 3-3 of Fig. l. and looking in the direction of the arrows;

Fig. i is a horizontal section view taken through the line 5%-4 of Fig. 2 and looking inthe direction of the arrows;

' VIn Figs. 1, 2, 3, and 4,parts are shown in section, and parts are broken away to illustratecertairi details of the construction.

Referring to the drawing, this invention has been shown in one form in Figs. 1, 2, 3, and 4 as applied to a lamp changer of the vacuum cup type comprising a pole i6 to the upper end of the pole En is attached the vacuum cup H.

The pole l0 has sufficient length so that a person standing on the floor and using the pole I0 can place the vacuum cup Il against the spherical or convex portion of an electric llamp bulb installed in an elevated socket. Preferably the pole In is cylindrical in form. The pole I0 .also has sufcient rigidity so that the movement of the vacuum cup l I can easily be controlled by a person grasping the lower end of the pole l0.

lll

other materials are found satisfactory.

. the recess creasing diameter.

The vacuum cup II and the foundation I2 comprise the flexible head I3. Preferably the flexible head I3 is formed as one unit. As shown in Figs. 1 and 2 the external form of the exible head I3 is preferably funnel shaped. The exible head I3 may be of any suitable material, but preferably will be of a good grade of flexible rubber. The foundation I2 shows one way by which vacuum cup I I is attached to the upper end of the pole I0. As shown in Fig. 4 the foundation I2 is preferably cylindrical in form and is preferably provided with a cylindrical hole I4. The lower end of the hole I4 is open, The upper end of the hole I4 is closed. The internal diameter of the hole I4 is preferably a little less than the external diameter of the upper end of the pole I0. In assembling the lamp changer, theupper end of the pole I0 is forced into the somewhat smaller hole I4. This causes the foundation i2 to grip rrnly the upper end of the pole I0. To insure further the adhesion between the upper end of the pole I0 and the foundation I2 and to insure that the pole IB can not be rotated independently of the vacuum cup II, glue may be used to fasten the upper end of the pole I0 into the hole I4.

The vacuum cup II provides means for gripping by vacuum any size from the smallest to the largest of the common spherical lamp bulbs or lamp bulbs having a convex lower end. To accomplish this, a recess I5 is provided in the upper end of the vacuum cup I-I. Preferably the recess I5 is inthe form of a frustrum of a right circular cone but may be in any other suitable form such as a right circular central recess of steadily de- The vertex angle of the cone of which the recess' I5 is a frustrum may Within reasonable limits be 4almost any value desired, but it has been found preferable to provide a recess which is a frustrum of a right circular cone having a vertex angle of approximately ninety degrees. As shown in Figs. l and 2 the frusto-conical recess I5 is located with 'the circular portion of largest diameter forming the open mouth or inner rim I6 of the recess I5, and with its circular portion of smallest diameter forming the lower closed bottom Il of the recess I5. The bottom I1 of the recess I5 is preferably concave in form.

The inner surface I8 of the recess I5 is preferably smooth. The wall I9 between the inner surfacel and the external surface 20 of the vacuum cup I I is preferably of substantial thickness, because when the vacuum cup II is used to grip large sized lamp bulbs, the contact between the bulb and the inner surface I8 of the vacuum cup I I is made at or near the inner rim I6 of I5. The wall I9 therefore should havesufllcient thickness and strength to be able to support the large sized lamp bulb in an approximately co-axial relationship with the pole I0.

Preferably at one point on the external surface 20 of the vacuum cup II near the outer rim 2I there is provided a means for attaching a cord preferably in the form of a lip 22. There is preferably a hole 23 through the lip 22. 'I'he lip 22 is preferably formed of the same material as the vacuum cup II and is preferably formed as one piece with the vacuum cup II. The hole 23 through the lip 22 is preferably reinforced with a metallic eyelet 24. By means of the hole 23 and the lip 22 there is attached to the outer surface 20 of the vacuum cup II a cord 25 which preferably extends from the lip 22 to a point near the lower end of the pole I0. 'Ihe cord 25 is preferably supported loosely along the pole I0 by being threaded through screw eyes 26. The cord 25 is preferably fastened to the pole III by a screw eye 2l at a point near the bottom of the p'ole I II.

In the operation of this apparatus, if it is desirable to remove a lamp bulb from an elevated I socket, the lower end of the pole I0 is grasped in the hand and by means of the pole I0 the recess I5 in the vacuum cupI II is pressed against the spherical or convex portion of the lamp bulb so that the bulb, the vacuum cup II, and the pole I D are all approximately in co-axial relationship one with the other, and so that the convex surface of the lamp bulb is approximately tangent to the inner surface I8 of the vacuum cup II. In other words the lamp bulb is inscribed into the recess I5. By means of the pole I0 the vacuum cup iI is pressed rmly against the lamp bulb in order to expel part of the air confined in the portion of the recess I5 below the convex surface of the lamp bulb. If the lamp bulb to be removed is small, the bulb makes contact with the inner surface I8 of the recess I5 fairly near the bottom I'I of the recess I5 as shown in Fig. 1. If the lamp bulb to be removed is large the bulb makes contact with the inner surface I8 of the recess I5 near the inner rim I6 as shown in Fig. 2. After part of the air has been expelled from the vacuum cup I I and the vacuum cup II has firmly gripped the lamp bulb, the lower end of the pole I0 is rotated. This rotates the vacuum cup I I which in turn rotates the lamp bulb and unscrews the lamp from the socket. After. the lamp has been disengaged from the socket it can be lowered and detached from the grip of the vacuum cup II.

If it is desirable to manipulate a lamp into an empty socket located in an elevated position, the convex surface of the lamp bulb is held against the inner surface I8 of the recess I5 so that the lamp bulb, the vacuum cup il, and the pole I 0 are all in approximately co-axial relationship one with the other. Then sufficient pressure is applied to the lamp bulb to force it against the Vacuum cup II so as to expel part of the air confined in the portion of the recess I5 below the convex surface of the lamp bulb. After the vacuum cup II has firmly gripped the lamp bulb,m the bulb is raised to the socket and is manipulated into the socket by rotating the pole I0 in order to screw the lamp into the socket.

After the lamp bulb has been manipulated into the elevated socket, the grip which the vacuum cup II has on the lamp bulb may be released by pulling the cord 25 which distortsthe shape of the vacuum cup lI sufciently to separate a portion of the inner surface It of the vacuum cup II from contact with the spherical or convex portion of the lamp bulb. This releases the grip the vacuum cup II has upon the lamp bulb, and permits'the removal of the lamp changer device.

Generally it has been found that the unmoistened vacuum cup II will grip the lamp bulb with sufficient power to allow it to be properly manipulated. However if increased gripping power is desired it may be obtained by moistening the inner surface I3 of the vacuum cup II with a little water or by breathing thereon.

l It is evident from the above description of my invention that lamp changers manufactured in accordance therewith are inexpensive, simple to construct, easy to operate, and adapted to handle any size of the various spherical lamp bulbs or any size lamp having a bulb with a `lower convex end.

The expression frustro-conical, frustrum of a cone and the like in the description and claims are intended to mean not only that which is left of a cone after cutting off an appreciable part of the point of the cone, but also is intended to include that which is left of a cone after an infinitesimally small part of the point has been cut off. In other words these expressions are intended to include what is generally considered a cone andl a frustrum of a cone.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. A lamp changer comprising .a pole, a vacuum vcup of flexible material mounted on the upper end of said pole, said vacuum cup having in its upper end a right circular central recess of steadily decreasing diameter, a smooth inner surface for said recess, and said inner surface acting as the `contact making surface when said vacuum cup grips a lamp bulb.

2. A lamp changer comprising a flexible head having in its upper end a centrally located right circular frustro-conical gripping recess with a smooth inner surface which inner surface acts as the gripping element, said flexible headl having point near the bottom of said pole, and a means for attaching said cord to the uppermost outer edge of said flexible head, whereby through the use thereof any sized lamp bulb can be removed from or manipulated into a socket located in an elevated position without the use of a ladder or the like.

3. A gripping device for lamp changers comprising a vacuum cup of flexible material having in its upper end a right circular central recess of steadily decreasing diameter, and a smooth inner surface for said recess, said inner surface acting as the contact making surface when said vacuum cup grips a lamp bulb.

4. A gripping device for lamp changers comprising a vacuum cup having in its upper end a frustro-conical gripping recess which is a frustrum of a cone having a vertex angle of approximately 90 degrees, means for attaching said vacuum cup to the upper end of a pole, and means for attaching a releasing device to said vacuum cup.

5. A lamp changer comprising a pole, a vacuum cup gripping device having in its upper end a frustro-conical gripping recess which is a frustrum of a cone having a vertex angle of approximately 90 degrees, means for attaching said vacuum cup to the upper end of said pole and means for releasing the grip of said vacuum cup.

6. A lamp changer comprising a pole, a vacuum cup gripping device having in its upper end a frustro-conicai recess which is a frustrum of a cone having a vertex angle of approximately 90 degrees, said recess having a concave bottom, a smooth inner surface for said recess, said inner surface acting as the contact-making surface when said vacuum cup grips any sized lamp bulb, means for attaching said vacuum c up to the upper end of said pole, and means for releasing the grip of said vacuum cup. l FORD C. PETHICK. l

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